Set sysctl values from Chef!

This is a fork of the sysctl cookbook from avishai combined with the work of damm for ease of use.

node[:sysctl] = A namespace for sysctl settings.

There are two three ways of setting sysctl values:

1. Set chef attributes in the sysctl namespace, E.G.:

   default[:sysctl][:vm][:swappiness] = 20

2. Set values in a cookbook_file - 69-chef-static.conf

3. Using the sysctl definition inside a cookbook

   sysctl "What am I doing" do variables 'kernel.sem' => node[:blah][:kernel_sem] end